The technical field of the invention is that of turbine engines, and in particular that of turbine engine fan blades made of composite material and having a leading edge including metal structural reinforcement, and the present invention thus relates more particularly to a method of high-temperature shaping metal parts, e.g. such as metal structural reinforcement for the leading edge of a turbine engine blade made of composite material.
Nevertheless, the invention is equally applicable to making any part of complex geometrical shape and to making metal reinforcement for reinforcing the leading edge or the trailing edge of a blade for any type of terrestrial or aviation turbine engine, and in particular for a helicopter turboshaft engine or for an airplane turbojet.
It is known to provide turbine engine fan blades that are made of composite material with metal structural reinforcement that extends over the full height of the blade and beyond its leading edge, as described in Document EP 1 908 919 filed in the name of the Applicant. Such reinforcement enables the composite blades to be protected in the event of a foreign body impacting the fan, e.g. a bird, hail, or indeed grit.
In particular, the metal structural reinforcement protects the leading edge of the composite blade by avoiding any risk of delamination, of fiber rupture, or indeed damage by loss of cohesion between fibers and the matrix. In known manner, it is made either entirely by milling a block of titanium, which requires numerous reworking operations and complex tooling, implying high fabrication costs, or else from a preform that is obtained from a simple metal bar by a succession of forging steps, as described in particular in French patent application FR 2 961 866 filed in the name of the Applicant.
Nevertheless, the last forging steps are particularly difficult to perform, given the presence of undercuts in the reinforcement. That is why the Applicant has developed “multi-effect” tooling for hot shaping as described in its patent application FR 2 965 496, that enables deformation to be performed three-dimensionally (i.e. simultaneously in different directions) by means of an inexpensive single-effect press (i.e. operating on only one working axis) under high-temperature conditions, i.e. above 850° C. (and around 940° C. for making reinforcement out of titanium).
Although that method is generally satisfactory in terms of its speed and simplicity, it nevertheless still presents certain drawbacks as a result of the way movements need to be linked for closing the tooling. As a result, the part that is to be made can be poorly positioned in the tooling, and it is also not easy to remove it from the recess during unmolding, which can lead to the part being deformed.